From Pathfinder Lost Omens Character Guide, which isn't enabled.

Life-Giving Magic

FEAT 1

Activity reaction

Frequency once per minute

Trigger You cast an innate spell from a gnome heritage or ancestry feat.

The upwelling of innate magic refreshes your body. You gain a number of temporary Hit Points equal to half your level (minimum 1) that last until the end of your next turn.

Pathfinder Lost Omens Character GuideOGL